The invention relates to an unmanned underwater vehicle having at least one sensor unit that can be used to acquire sensor information relating to objects in the area surrounding the underwater vehicle. The invention also relates to a method for operating an unmanned underwater vehicle with at least one sensor unit used to acquire sensor information relating to objects in the area surrounding the underwater vehicle.
In contrast to manned missions, unmanned underwater vehicles can reach greater working depths and can operate in environments which are too dangerous for divers or manned underwater vehicles. Unmanned underwater vehicles are also able to perform most of the tasks which were previously carried out by larger research ships. Unmanned underwater vehicles therefore afford a large cost advantage over manned systems. Unmanned underwater vehicles can be roughly subdivided into remotely controlled underwater vehicles (ROV=Remotely Operated Vehicle) and autonomous underwater vehicles (AUV=Autonomous Underwater Vehicle).
Remotely controlled underwater vehicles (ROV) are generally remotely controlled via a connection cable, usually by a human operator. Remotely controlled underwater vehicles are preferably used for missions with locally limited, more detailed investigations under real-time conditions, the underwater vehicle often also having to act on an object under water, for example for repair purposes.
Autonomous underwater vehicles (AUV) perform their respective mission without being continuously monitored by human operators but rather follow a specified mission programme. Autonomous underwater vehicles comprise their own power supply and do not require any external communication during the mission. After the mission programme has been carried out, the autonomous underwater vehicle independently surfaces and is then recovered. An autonomous underwater vehicle is particularly suitable for large-scale reconnaissance under water and investigates the underwater environment, generally without contact with sensed objects under water.
Unmanned underwater vehicles, that is to say both remotely controlled underwater vehicles (ROV) and autonomous underwater vehicles (AUV), comprise at least one sensor unit which can be used to acquire sensor information relating to objects in the area surrounding the underwater vehicle. Remotely controlled underwater vehicles often use a camera, as a sensor unit, to record images under water which are displayed to the operator in order to make it possible for the operator to carry out an inspection or manipulations under real-time conditions using images of an object. Autonomous underwater vehicles require sensor units to sense objects in the area surrounding the underwater vehicle for various tasks. The sensor information is used, inter alia, for navigation. The sensor information is also used to locate objects or to calculate manoeuvres for the closer inspection of underwater objects which have been found.
Both large-scale reconnaissance or investigation and locally limited work under real-time conditions are required in a multiplicity of underwater missions, for example when inspecting and, if necessary, repairing offshore installations, for example pipelines. Walls, in particular vertical walls, often need to be examined under water, the walls having to be covered over a long inspection range according to their length under water. If damage is detected, the damage must be diagnosed in more detail and repaired, if necessary. Such fields of use of unmanned underwater vehicles are, for example, harbour inspections including the inspection of channel walls, quay walls, sheet pile walls etc., in particular with regard to the undermining of such underwater walls. Harbour inspections can also concern the examination and possibly manipulation of hulls. During such underwater missions, objects having extensive structures and contours need to be investigated and must be comprehensively scanned by the sensors of the underwater vehicle. In this case, the structures and contours of the investigated object may change, with the result that the sensor unit cannot sense the structures and contours of the object at all or can sense them only inadequately.
The sensor units are permanently mounted in known unmanned underwater vehicles but it is not possible to adapt the sensor unit to changing structures and contours of the object to be investigated. Control manoeuvres of the underwater vehicle are therefore regularly needed to bring the sensors into new positions with respect to the underwater body to be investigated in order to obtain suitable sensor information. Adjustment manoeuvres therefore often have to be carried out by an operator when investigating extensive underwater bodies such as underwater walls or ship walls, thus slowing down the performance of the mission.
So-called pan-tilt units are known from monitoring technology, which are a mechanical gearbox, which can carry out tilt movements and pan movements in a coordinated manner, and in which a camera tracks a target. Such pan-tilt units are used, in particular, to monitor rooms, the camera sensing movements, in particular of persons who intrude. Such pan-tilt units are not suitable for use in unmanned underwater vehicles since the camera and possibly the light source are manually set and oriented by an operator and a large amount of time is therefore needed to adjust the sensors. On account of the remotely controlled operation of the pan-tilt units, such systems are, in particular, not suitable for autonomously operating underwater vehicles (AUVs).
The invention is based on the problem of sensing structures and contours of objects under water as quickly and accurately as possible.